def login(username, password, code):
    # 1. 先验证验证码，验证码正确前提下，再验证用户名和密码
    if code == '8888':
        if username == 'admin' and password == '123456':
            return '登陆成功'
        else:
            return '用户名或密码错误'
    else:
        return '验证码不正确'
